1. Field of the Invention
The present invention is directed to a novel class of dioxo heterocyclic carboxamide compounds. More specifically, the instant invention is directed to a class of substituted dioxo heterocyclic carboxamide compounds useful as plant growth regulants.
The importance of plant growth regulants to the economic viability of agriculture continues to grow in importance. This is to be expected in view of the important functions provided by these agricultural chemicals. Plant growth regulants are now for dwarfing, cessation of terminal growth, inhibition of axillary and intercalary growth, increase in plant yield and the like. These applications are not only essential to economic viability, which results from increased production of economically important crops, but, in addition, they are also of increasing utility in the successful production of ornamental plants. It goes without saying that plant growth regulants greatly improve the appearance of ornamental plants, without the requirement of difficult and expensive manual labor.
An important characteristic of plant growth regulants, which excludes many otherwise effective compounds which regulate plant growth, is the requirement that they exhibit low foliar phytotoxicity. That is, an effective plant growth regulant must not only retard vegetative growth and provide the functions discussed above but must also do so without being toxic or in any way have any adverse effect on the plant other than regulating its growth.
Among the more important commercial agricultural plants are wheat and barley. These crops are beneficially affected by control of their growth in that such control optimizes yield of these important grains.
2. Background of the Prior Art
There is a dearth of prior art directed to dioxo heterocyclic compounds substituted with carboxamides. A class of dioxo heterocyclic compounds is identified in Kuznetsov et at., Ukr. Khim. Zh., 42 (10), 1063-1067 (1976). An English abstract of this Russian language article appears in Chemical Abstracts at CA 86 (7):43631z. Kuznetsov et al. discloses 5,6-N-phenyl-2,4-dioxin-2-carboxamide and 5,6-dihydro-N-4-chlorophenyl-1,4-dioxin-2-carboxamide. These compounds are not recited to possess any specific utility and are distinguished from the class of 5,6-dihydro-3-methyl-N-phenyl-1,4-dioxin-2-carboxamide compounds.